I'm relatively new to Corn snake ownership (about 2 months) and had some difficulties with culling the pinkies. I noticed that new owners often wonder how to cull humanely.
I could not bear the thought of freezing them alive and did not want to "bludgeon" them to death. And I think gassing by CO2 will take too long, thereby increasing stress and suffering.
I then decided that I will use electricity. I used it on two different occasions to cull 13 in total so far. It's basically instant and is relatively non-violent.
What I did:
1. I took two plugs (one three-prong and one two-prong) with some cord attached and joined the cords end to end. Ensuring that it's decently insulated with insulation tape.
2. I plugged in the 3-prong and put on a rubber glove on one hand to handle the 2-prong plug with and with the other placed the pinkies one by one on a plastic container lid, culling each as it is put on the lid.
3. Keep the contacts only for a second or two in contact with the pinkie. No longer than 2 seconds!
Do not do this if you are a minor. The risk of electrocuting yourself is very real if you are careless.
I know it's not a perfect method, but it works perfectly for me. Hope this can help someone